“…Using the force/power rig, initial tests investigating the effects of ultrasonic amplitude, penetration speed, sand choice and relative density were conducted [ 7 ], as presented in figure 6 . These tests showed that application of ultrasonic vibration has a large impact on the peak penetration force, where the greatest reduction occurred at the lowest vibration amplitude, 1 µm, with diminishing returns at higher amplitudes.…”
Section: Resultsmentioning
confidence: 99%
“… Figure 6. Maximum encountered penetration force as a function of ultrasonic amplitude used [ 7 ]. (Online version in colour.)…”
Section: Resultsmentioning
confidence: 99%
“…Initial tests used a total of five different regolith simulants. Four of these were published simulants SSC-1, SSC-2, SSC-3 and ES-3, with an additional block paving sand, referred to as 'BP' in this article [7,[16][17][18]. The simulants were run through a set of progressively finer sieves, and the resultant sand mass of each division was measured to calculate the distribution of particle sizes within the samples.…”
Section: Experimental Characterization and Calibrationmentioning
confidence: 99%
“…Both the USDC/UPCD and the DRD mechanisms allow for significantly reduced required overhead forces for drilling. In a related system, the direct application of ultrasonic vibration has been shown to reduce required overhead penetration forces in granular material by fluidizing the surrounding substrate [ 7 ].…”
This work investigates the potential use of direct ultrasonic vibration as an aid to penetration of granular material. Compared with non-ultrasonic penetration, required forces have been observed to reduce by an order of magnitude. Similarly, total consumed power can be reduced by up to 27%, depending on the substrate and ultrasonic amplitude used. Tests were also carried out in high-gravity conditions, displaying a trend that suggests these benefits could be leveraged in lower gravity regimes.
“…Using the force/power rig, initial tests investigating the effects of ultrasonic amplitude, penetration speed, sand choice and relative density were conducted [ 7 ], as presented in figure 6 . These tests showed that application of ultrasonic vibration has a large impact on the peak penetration force, where the greatest reduction occurred at the lowest vibration amplitude, 1 µm, with diminishing returns at higher amplitudes.…”
Section: Resultsmentioning
confidence: 99%
“… Figure 6. Maximum encountered penetration force as a function of ultrasonic amplitude used [ 7 ]. (Online version in colour.)…”
Section: Resultsmentioning
confidence: 99%
“…Initial tests used a total of five different regolith simulants. Four of these were published simulants SSC-1, SSC-2, SSC-3 and ES-3, with an additional block paving sand, referred to as 'BP' in this article [7,[16][17][18]. The simulants were run through a set of progressively finer sieves, and the resultant sand mass of each division was measured to calculate the distribution of particle sizes within the samples.…”
Section: Experimental Characterization and Calibrationmentioning
confidence: 99%
“…Both the USDC/UPCD and the DRD mechanisms allow for significantly reduced required overhead forces for drilling. In a related system, the direct application of ultrasonic vibration has been shown to reduce required overhead penetration forces in granular material by fluidizing the surrounding substrate [ 7 ].…”
This work investigates the potential use of direct ultrasonic vibration as an aid to penetration of granular material. Compared with non-ultrasonic penetration, required forces have been observed to reduce by an order of magnitude. Similarly, total consumed power can be reduced by up to 27%, depending on the substrate and ultrasonic amplitude used. Tests were also carried out in high-gravity conditions, displaying a trend that suggests these benefits could be leveraged in lower gravity regimes.
“…Ultrasonic vibrations have been applied to granular material not just for compaction. For example, ultrasonic penetration into sand has been investigated for planetary drilling [18], where the application of ultrasonic vibrations has been shown to reduce the measured force on the penetrator/drill by generating fluidised behaviour in the granular material. In the vibration of granular material such as sand particles, it is known that there is a stage at which the particles begin to behave more like a fluid than a solid.…”
It has been shown that the compaction of granular materials for applications such as pharmaceutical tableting and plastic moulding can be enhanced by ultrasonic vibration of the compaction die. Ultrasonic vibrations can reduce the compaction pressure and increase particle fusion, leading to higher strength products. In this paper, the potential benefits of ultrasonics in the compaction of geological granular materials in downhole applications are explored, to gain insight into the effects of ultrasonic vibrations on compaction of different materials commonly encountered in sub-sea drilling. Ultrasonic vibrations are applied, using a resonant 20kHz compactor, to the compaction of loose sand and drill waste cuttings derived from oolitic limestone, clean quartz sandstone, and slate-phyllite. For each material, a higher strain for a given compaction pressure was achieved, with higher sample density compared to that in the case of an absence of ultrasonics. The relationships between the operational parameters of ultrasonic vibration amplitude and true strain rate are explored and shown to be dependent on the physical characteristics of the compacting materials.
This paper describes the effects of ultrasonically-assisted penetration of granular materials, in high gravity situations. The experimental rig, instrumented to obtain penetration force, rate and power both with and without ultrasonic assistance, was used to drive a penetrator into a granular material inside the ESA Large Diameter Centrifuge at accelerations of up to 10 g during early September 2015. Ultrasonic penetration proved to be most beneficial at lower levels of accelerations, reducing the required overhead weight by 80%, and the total power consumption by 27%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
